The present invention relates generally to water heaters. More particularly, the present invention relates to a water heater in which a primary heating arrangement (e.g., electric or gas) is supplemented by a photovoltaic heating arrangement.
Typical water heaters have a tank in which a quantity of heated water is maintained for use as needed. Generally speaking, such water heaters fall into one of two categories, i.e., electric or gas, depending on the type of heat source used to bring the water in the tank up to the desired temperature. Electric water heaters, for example, are often configured having two electric heating elements near the top and the bottom of the tank, respectively. Typically, the heating elements are energized by AC voltage (such as 240 VAC or others) which is turned on and off as necessary to maintain the desired temperature.
In this regard, electronic or bimetallic thermostats are used to regulate the water temperature by sensing the water temperature and allowing the voltage to be applied to the heating element(s) when heat is needed. Heat loss over a period of time (i.e., standby loss) or usage of the water heater capacity determines the demand for hot water. Thus, tanks that exhibit greater heat loss in the idle state are less efficient than those that exhibit less standby heat loss because more electric (or gas) energy is required to maintain the desired temperature. Efforts have thus been made to increase efficiency by providing better insulation for the tank. However, even very well insulated water heaters experience some standby loss.
The present invention recognizes the foregoing considerations, and others, of the prior art.